Method of forming electrodes



April 25,f 1944. E PENKER y 2,347,501

vmmol) oFA FORMING ELECTRODESl VFiled Nov. e', 1942 ,vfsz ng. l. A3 Figa ulm-W- :Ill-nj 5 ze un l, ,24- .f f i f INVENTOR. Ernest Pemr Patented Apr. 25, 1944 UNITED STATES PAT-ENT OFFICE 3 Claims. (C1. ,2s-155.757)

This invention relates generally to metal stamping and is moreparticularly directd'to a method of producing an'electrode from a'n'etal blank in a form t9 function as a base vfrsii'pporting a crystal. as feed i111 fadi pp'arts' for example, in a single stamping operation.

the use of a piezo' crystalfff instance, in the operation of radio apparatus, the crystal 'is supported one. rigid base of a rectangulafsl'ape produced from a metal ofthe requisit'electrical conductiyity characteristics, the blank,-` under.

present"methods"of` manufacture; being4 machmod; aswb'y'a'millingV operation, to undercut thesurfacefmaterial being left at each of -.the fouri corners to "rm abtments or" shoulders pppn which' the c fystar is to "reet, theY undercut prtion'of 4*the` surface' of "the completed electrode being spaced from theshulderlsuppcirted' crysta'lto prei/ide an" aisp'ace'be'neath the crystal and permit of'pcl'ar Vibration thereof,'between its supported corners.' The crystal-supporting shouldersare Vdeined'by Ytl'i'e meeting side edges 'of the blank" anda connecting arcuate surface the plane ofthe'peripher'al dglefof the blank, the nsetiee sdgesvfiig 'a' 'right' anglev @Xtefr .9i the are am@ th eeslrlef ihuldrs anon which the .brystal is .iinpqriedf rlatve t0 the ,underc'ut are@ Vbetr/,6.11 119,.Shf211llrs, .does not exceed tw@ @ne .widths Aoff inch, ,it .will ,be evident ,that the. .utmost precision vis rie.- quiredin setting upthe werk and in th operation ef the milling cutter, .by .one skilled .in .milling machine operation, in manyinstances `a final lapping .operation .being ,necessary to .attain the requisite aceuracyin .the ultimate product. This makes for high production .costs and, '.under the ratus `Wl'ieijeby the `electrodesf.'rray 'be rapidly n and precisely formed blank o f metal'n e .Single ,Stamping @pertn in 'manner fo eliminate the necessity jQr any lsubsequent `machipping, thereby materially reducing the cost of the electrodes, and, wat is more important, providing `fr high speesiiuantity produticn ,It is alsoan.important'object.of this Vinyention ,to provide means fcrcpni/rting airect'ar'i ular `blank Qf`metal havinggla vtitille" leyel surface into an electrode er crystal Suppcrt, by eiecting the t"bf""nate ria1"between the corner 4va ydirectionparallel to V ,l rm ned arriount, in asin'gle Hearing Qperatlpfn under concentrated fthe 'electrode lthus produced being in @te feriti iffQr'funtQnig as a .C''YStal .6. Cf' my lvmn is 130i pro aforesaid, for producing an "a 'rneta lb lank, embodying 'Shoulonally opposite corners thereof I ssedvl majprsui'ffgce between the fsf :u-lfdersbY" 'flelctn'g "a .u'nifqrm displacement l5 lf'tl metal ofthe' blank inwardly ofthe shoultierv i limbes there@ gary in the direcvti c metall displacingpressureis A the blank',so "that the' surfaces of J "s A:fiuld vsyVhi'cli are parallel to the outer peeet the surfvacfe formed l n portae metal therebetween' at cleanly' defined angle Off 90," as 'might' bebbt dfin a` carefully executed millingfpeaton, `result 'being'attained by re- 25 str pg the metal' against the latersvil flow or vementfunder pressure'that occurs in the con'- ye'nti'nal so-"called `c'oiiiing operation. er objects vand advantages which flow from yentidn wiuppegome inamnDrceeds and' I would have I f n .yli e I have elected to con'- iine thisiii/*scipsre 4to hepro'ductin of an electljole .9i @"e'ef orl'ffrmlatin'fas usedlfo a ,particula'r`- purpl le, ivntifiimay be utilized j; ure ofelectrcdes enbase-'forniins @lemen Qf teef semeel Charafeiifcs. .Qr .other purposes In the accompanyingdrawing, I have shown a specific term ,ci ,electmde which Iiyxb duced .by my method. together ,with an araheement `cf `.rriellfiili$11.1nr means whereby ,my mathod may be carried into effect, it being evident ,manine shapetof vthe ele trcder ensiprroduct V,obtained in .thegpracticingbf my method may .yary imm .that gherein shown, v.as may .be predetermined lby .shape 'Lof the .coacting forming means. f. C. In the drawing-' `Figure 1 -is" 'a plan View of a blank from which the "elecfftr'odeis`r f'r'riiedlinE a 'single operation."

figur j pieviewiof thecompleted'elecnode,

g ""a shoulder" at 'each corner, splacexn nt 'of the metal' there- Figure 3 is a diagonal sectional view, on a magnified scale, on the line 3-3 of Figure 2. Figure 4 is a fragmentary plan View of the lower part of the mechanism, showing the insert or female die section and the work-retaining nest elements, magnified for clarity; and

Figure is a sectional elevation along line 5-5 of Figure .4, of thecoacting'elements of a mechanism for `practicing my invention.

Referring now to the drawing in detail, in which like characters of reference are employed to designate similar parts in the several views, the blank, indicated at I0 in Figure 1, which is rectangular in shape, is punched out of sheet y or strip material of the appropriate thickness,

the surface which is to be processed in the shearj ing operation being lappedto render it perfectly smooth and insure absolute uniformity of the cross-sectional area of the blank.

The lapped blank is then located within a nest of a contour complemental to the peripheral edge II of the blank and supported from beneath in juxtaposition to the four corners thereof by appropriately formed surfaces of the bed carrying a female die element, the same, as mounted, beingy depressed against such corner supporting surfaces to provide an area between the corners of the blank in which the latter is unsupported, for the performance ofthe shearing operation, as hereinafter explained. The displacement of the met-a1 is effected under pressure applied to the upper surface of the blankv in the direction of the aforesaid depressed female die element, to form the shoulders lI2 and the depressed area I3 therebetween. As will be observed, each of the four shoulders is defined by an arcuate surface I4 in the plane of the peripheral edge of the blank, the-edge portions IIa, IIb, connected by said arcuate surface lIc, meeting at a right angle eX- terior of the latter, as will be apparent.

Y The aforesaid depressed. area I3 between the shoulders I2 of the electrode is formed by the uniform displacement of the metal of the blank solely in the direction in which the displacing pressure is applied, in a predetermined amount,

as for example, two-thousandths of an inch, the Vertical arcuate surfacesld of each of the shoulders I2 meeting thehorizontal depressedsurface I3 at an angle of 90 vthroughout its length. In this controlled and uniform displacement of the metal only in the direction in which the displacing 'pressure is applied to the blank, an

amount equivalentv to the material displaced between the shoulders I2 is extruded from the opposite or under surface of the blank, as indicated at I5, within the unsupportedvarea thereof, in the practicing of my method, as by the means hereinafter described. The resulting end product is precisely dimensioned to efficiently perform its intended function as a crystal support, no subsequent lapping or machining operations being required to condition it for. use.

As shown in Figures 4 and 5,- aconventional -punch press or stamping machine may be employed in practicing my method, thegeneral construction and mode of operation of which 1s well known and, in view of which, I have illustrated only so much of the machine structure as is essential to a clearundevrstanding of the procedure which Ifollow inconditioning the mechanism for carrying my vrriethod into effect.

As herein shown,V the mechanism includes a male punch or die V carried byt'he usual central slide orram, with which -the head 2| is movable, a pressure'plate v22 being suspended' from the head by screws 23 for relative vertical movement under the influence of and in opposition to the coil springs 24 within bores I8 and I9, the heads of the screws 23 being vertically movable within the counterbores I1 of the head, to provide for movement of the pressure plate toward the head in the progression of the punch or male die 20 to its workengaging position', as will be explained. f

A bed 25 is recessed as at 26 for the reception of an insert or female die element 21 of circular cross-section, which is mounted below the surface of the bed to form a central vertical de- 1 pressed area 21a, thesurfaces of the bed bounding the depressed area at the four corners of the insert and indicated at 21h, functioning to support the blank at its respective corners and to cooperate with the male die and the surface of the pressure plate contiguous thereto, in the formation of the shoulders I2 of the electrode, the metal displaced in the latter operation, indicated at I5, enteringinto the recess 26 above the insert or die element within the arcadepressed 21a. A so-called nest',- which may be of a unitary or sectional construction, and indicated at 28, is fixed to the upper surface of the bed 25 by the screws 29 or other suitable media.

The nest 28, as Vwill be apparent; vdefines the work position and provides an opening 28a com-- `21a of said' die element, as shown in Figure 5.

As will be noted, the pressure plate 22 is recessed, as, at 30, to register with the opposed surface of thenestv 28 in the descent of the central slide, the base of the recess being counvtersunk, as 'at 3l, for the reception of the heads of the nest-securing screws 29. The height of the nestforming members is approximately onehalf of the thickness of-a blank disposed in the nest'opening 28a,'the recess 30,-in the head 22 complemental to the nest, being of a corresponding depth for accurate registration of the opposed vsurfaces.Y The surface surrounding the -male die position of the `pressure plate 22 is recessedas at 32 to provide for the cooperation .i of the male die vwith the female. die element 21,

the depth and area of such recess corresponding to the height and area of the peripheral edge of the blank as exposed above the nest 28, the effec- Avtive surface of the male die orpunch 20 being of the same cross-sectional area and configuration as the insert or female die 21. Y

For performing an electro-forming operation, the work, `indicated at w in Figure 4, is located in the nest opening 28g, with its corners abut- Y.ting upon the surfaces 2113 bounding, the female vdie 21, and spanning the depressed or undercut area 21a thereof, the height of the corner-engaging surfaces 21b bounding the .female die elementrelative to the central depressed area -21a thereof, being .accurately proportioned to providefor the displacement of the necessary metal underV the pressure of the male die in the formation of the electrode. `As the central slide descends, it will be manifest that .the pressure plate 22,. suspended from 4thefh'ead ..2I, will abut 'upon the "opposed -'surface' of" the bed 25 with its recess 3G in registration with the nest 28 and the inner recess 32 in registration with the cooperating surfaces of the work in the nest opening 28a; The initial downward movement of the central slide will compress the springs 24, the head 2| impinging upon the pressure plate 22 to urge it toward the bed 25 to firmly clamp the work between the opposed cooperating surfaces bounding the die element 21 and the pressure plate. In appropriately timed relation to the application of the clamping effort to the work, as just described, the male die or punch 2E), in the continuing descent of the central slide, impinges upon the work to effect the displacement, by shearing action, of the metal within the unsupported area of the blank, as defined by the coacting surfaces of the two die elements, in the direction of movement of the male die, to extrude the excess metal in the same direction into the depressed area 21a of the female die element 21, in the completion of the electrode-forming operation.

Since the male die is of the same diameter and cross-sectional configuration as the female die element or insert 21, the effective vertical surfaces thereof forming a true right angle with their horizontal surfaces, the direction of movement of the metal in its displacement under pressure of the impinging male die or punch 2U is positively controlled, the vertical surfaces at the die position coacting to direct the metal in its displacement in a path parallel to the axis along which the pressure is applied thereto, and effectively preventing lateral flow or spreading, as obtains in the usual coining operation. Obviously, by restraining lateral flow or displacement of the metal, as it is compacted under the punch pressure, it can yield only in the direction of movement of the punch for final displacement into the area 21a of the female die 21, the demarcation between the vertical arcuate surfaces I4 of the shoulders I2 of the electrode and the horizontal depressed area I3 formed therebetween in the displacement of the metal, being sharply and cleanly defined, as a result of the shearing action induced by the coacting male and female die surfaces, the curved surfaces of the crystal'- supporting shoulders meeting the horizontal surface I 3 at an angle of 90, it being understood, of course, that the arcuate surfaces Ill of the respective shoulders are complemental to the vertical surfaces of the male die which are effective in the formation of the shoulders, in the metal displacing operation.

As previously pointed out, the depth of the surface I3, relative to the parallel plane of the shoulders I2, at the corners of the electrode, is usually about .002 of an inch, so that it will be apparent that in order to provide the necessary clearance between a crystal mounted upon the shoulders I2 and the depressed area I3 of the electrode, absolute precision in the gauging of the surface i3 below the crystal-engaging top surfaces of the shoulders is not essential, but the vertical surfaces of the shoulders must meet the horizontal surface I3 at a sharp angle, such as I obtain in the practicing of my method, to insure a uniform spacing of the crystal relative to the depressed surface I3, throughout the area in which the crystal is unsupported, to admit of the vibration of the crystal in performing its intended function when supported by the electrode. Obviously, were it attempted to produce an electrode in accordance with the usual coining operation, such essential condition could not obtain,

as the lateral flow of the metalin its :displacement would build up the :density thereofinlthe area of the jointure of the vertical surfaces vof the shoulders with the horizontal depressed-surface therebetween, with rthe result that there would be .aA lack of uniformity in the relative vertical spacing of the unsupported area of the crystal and the opposed electrode surface I3, with the attendant inefficiency in the functioning of the crystal and the apparatus of which it may be an important element. By my method, uniform spacing of the unsupported area of the crystal relative to the area I3 of the electrode is assured, together with perfect performance of the crystal and the electrically coacting electrode.

Manifestly, the height of the shoulders I2 may be varied, as may be predetermined, to meet operational requirements, such changes in dimensions in the completed electrode as may be requisite for a particular service being effected in the practicing of my invention, by employing cooperating dies and work-retaining means of the appropriate sizes and configuration, for turning out the work in the manner hereinbefore set forth.

Although the pressure plate, as shown in the preferred adaptation of this invention, has been provided with a recess 32, for registration with the exposed surface of the blank wit is within the province of this invention to eliminate this particular guide mechanism so long as the blank is firmly nested in relation to the female die 21 and the male puncher die 20 is in alinement for cooperation with the female die as aforesaid.

I claim:

1. A method of forming an electrode for supporting a crystal or the like in the functioning of radio apparatus, which comprises forming a rectangular blank, immovably supporting said blank at its diagonally opposite corners, applying pressure to the surface of the blank in the area of its unsupported portion defined by said corners to displace the metal constituting said unsupported portion, in a shearing action, to a position below the corners, and simultaneously restraining the metal from spreading laterally in its displacement under pressure to form diagonally opposite vertical abutments dening a depressed area therebetween.

2. A method of forming an electrode for supporting a crystal in the functioning of radio apparatus, which comprises forming a rectangular blank, immovably supporting the diagonally opposite corner portions of said blank in a horizontal plane, applying vertical pressure to the surface of the blank in the area of its unsupported portion defined by the im'rnovably supported corner por-tions, to displace the metal constituting said unsupported portion to a position below that of the corner portions in a plane parallel thereto, and simultaneously controlling the displacement of the metal to prevent lateral spreading thereof under pressure, to form a horizontal surface in depressed parallel relation to surfaces of the corner portions and diagonally opposite vertical surfaces meeting such horizontal surface at an angle of 3. A method of forming an electrode from a rectangular blank, for supporting a crystal in the functioning of radio apparatus, which consists in immovably supporting the corner portions of the blank, applying pressureA to the surface of the blank, in the area of the unsupported portion thereof defined by said immovably supported corner portions, in a direction perpendicular to the plane of the surface of the blank to displace the metal constituting said unsupported portion relative to the corner portions, in a shearing action, and simultaneously conining the displacement of the metalgto a path parallel -to the axis along which the pressure is applied,

to form abutments at the corners of the blank and a depressed surface therebetween, in a plane parallel to the plane of the corner portions, said depressed surface meeting surfaces of the abutments at an angle of 90.

ERNEST PENKER. 

